Officials are probing how a 51-year-old highway bridge came to collapse in the Italian port city of Genoa yesterday, killing at least 26 people and injuring 16 others as it sent dozens of vehicles tumbling into a heap of concrete and twisted steel.

Ex-boxer hospitalised after Melb attack

A Melbourne man is under police guard in hospital after reportedly being bashed with a brick when he attacked his former partner with a claw-hammer.

Victoria Police say the 45-year-old remains in a critical condition after the incident in Bundoora on Saturday afternoon, after which a 44-year-old woman was also taken to hospital in a serious condition.

The Age reports the arrested man is ex-boxer Adrian Stack.

The BoxRec website says Stack won two of his four professional fights between 2002 and 2003.

It's reported Stack attacked his former partner with the hammer before her male friend, 42, bashed Stack with the brick.

Police say all three people involved were known to each other.

The woman was taken to the Royal Melbourne Hospital with injuries to her upper body, an ambulance spokesman said on Tuesday.